Camera system

ABSTRACT

A camera system including a camera body having a focus adjusting mechanism, a photographic lens having a diaphragm adjusting mechanism and a power zoom mechanism incorporated therein, an object distance measuring device, and a drive for driving the focal length adjusting mechanism of the photographic lens, so that the photographic lens and the camera body are compatible with conventional camera body and photographic lens.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a camera system for a single-lensreflex camera having an interchangeable lens, and more precisely itrelates to a compatible camera system having an automatic focusingfunction, automatic exposure function and electrically driven power zoomfunction.

2. Description of Related Art

A single-lens reflex camera usually has an interchangeable lens, andaccordingly, it is necessary to provide means for transmitting datapeculiar to the lens, such as an open F-number (minimum F-number) whichis used for an automatic exposure function and an automatic focusingfunction to a camera body in which the necessary arithmetic operationsare effected.

To this end, a conventional photographic lens has a lens ROM whichstores information peculiar to the photographic lens. A group ofelectrical contacts are provided, both on the camera body and on thephotographic lens, so that when the lens is mounted to the camera body,as disclosed for example, in Japanese Unexamined Patent Publication No.63-184719, which is co-pending as U.S. Ser. No. 266,328 and filed by thesame assignee as the present application the lens is electricallyconnected to the camera body. The entire disclosure of the co-pendingU.S. patent application Ser. Nos. 266,328 and U.S. Ser. No. 143,900 areexpressly incorporated by reference herein.

In a conventional single-lens reflex camera, data necessary for thearithmetic operations are transmitted only in one direction, i.e. fromthe photographic lens to the camera body, so that based on the data, thefocusing operations, actuation of the diaphragm and change of the focallength, etc. are effected by a driving power which is supplied from thecamera body.

Recent motor technique developments make it possible to provide acompact and small motor as a driving source on the photographic lenswithout increasing the size of the lens as a whole.

A single-lens reflex camera is usually intended to be used withdifferent photographic lenses having different steady information (fixedinformation), so that when the number of parameters to be controlledincreases, a control unit provided in the camera body needsprogressively increased arithmetic capability, resulting in an increasedburden on the camera body.

Accordingly, it is preferable that the individual photographic lensespossess data processing capability for the various functions of thephotographic lenses.

An advantage of the present invention is that a new camera system(camera body or photographic lens) is compatible with a conventionalcamera system (photographic lens or camera body).

SUMMARY OF THE INVENTION

The primary object of the present invention is to provide a photographiclens which can supply information for various functions of a camera bodyto a camera body. The photographic lens can be applied not only to acamera body having memory means and arithmetic means incorporatedtherein, but also to an automatic exposure control camera body (AEcamera) or an automatic exposure and focus control camera body (AEAFcamera).

To achieve the object mentioned above, according to the presentinvention, there is provided a photographic lens that is detachablymounted to a camera body, comprising a group of electrical contactswhich are to be connected to the camera body, first information transfermeans for transmitting a first information set peculiar to the lensthrough a part of or all of the electrical contact group, a secondinformation transfer means for transmitting a plurality of variableinformation peculiar to the lens through memory means connected to theelectrical contact group to the camera body, a third informationtransfer means for transmitting and receiving information to and fromthe camera body through an arithmetic/control means connected to theelectrical contact group, and, switching means for either selecting thefirst information transfer means, second information transfer means orthird information transfer means, in accordance with the state ofconnection of the electrical contact group to the camera body.

Another object of the present invention is to provide a camera bodywhich can transmit and receive information to and from the abovedescribed photographic lens a photographic lens having a conventionallens ROM, or a photographic lens having only diaphragm valueinformation.

To achieve the above-mentioned object, according to another aspect ofthe present invention, there is provided a camera body to which aphotographic lens is detachably mounted, comprising a group ofelectrical contacts provided on a camera body mount to which thephotographic lens is mounted, means for judging the type of photographiclens in accordance with the state of connection of the photographic lensto the electrical contacts, first control means for controlling thephotographic lens in response to a first information set whichrepresents a first lens type in which the photographic lens suppliesonly the first information set to the camera body, second control meansfor controlling the photographic lens in response to a plurality ofsecond information which are peculiar to the photographic lens and whichrepresent a second lens type in which the photographic lens supplies thesecond information to the camera body through a memory means connectedto the electrical contact group, and, third control means forcontrolling the photographic lens in response to a third information setwhich represents a third lens type in which the photographic lens has anarithmetic/control means connected to the electrical contact group inaddition to the memory means and receives and transmits the thirdinformation to and from the camera body.

Still another object of the present invention is to provide asingle-lens reflex camera system in which the transmission and receptionof information can be effected with high precision between a camera bodyand a photographic lens.

To achieve this object, according to another aspect of the presentinvention, a camera system is provided comprising a photographic lensand a camera body as mentioned above, respectively, in combination.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be described below in detail with reference to theaccompanying drawings, in which:

FIG. 1 shows a diagram corresponding to a photographic lens relating tothe present invention;

FIG. 2 shows a diagram corresponding to a camera body relating to thepresent invention;

FIG. 3 shows a block diagram representing a first embodiment of thecamera system according to the present invention;

FIG. 4 shows a front view of the new camera body of FIG. 2;

FIG. 5 shows a front view of a new lens mount that is part of the lensdescribed in FIG. 1;

FIG. 6 shows a circuit diagram of the new camera body;

FIG. 7 shows a circuit diagram of the new lens;

FIG. 8 shows a block diagram representing a combination of the newcamera body and a conventional AEAF lens;

FIG. 9 shows a circuit diagram representing the conventional AEAF lensshown in FIG. 8;

FIG. 10 shows a front view of the lens mount shown in FIG. 9;

FIG. 11 shows a front view of the mount of a conventional AEAF camerabody;

FIG. 12 shows a descriptive diagram of a conventional camera AE body;

FIG. 13 shows a descriptive diagram of a conventional AE lens;

FIGS. 14, 15, and 17 to 19 show flowcharts representing operations ofthe display CPU of the new camera body;

FIG. 16 shows a timing chart of the process of FIG. 15.

FIGS. 20 to 22 show flowcharts representing the operation of the mainCPU of the new camera body;

FIGS. 23 and 24 show flowcharts representing the operation of the lensCPU of the new lens.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT

In the following description, a camera body and a photographic lenscorresponding to the present invention are referred to as a new body anda new lens hereinafter to distinguish them from camera bodies and lensesused in conventional systems.

A new lens 3 relating to the present invention, which is detachablyattached to a camera body 1 comprises, as shown in FIG. 1, a group ofelectrical contacts 100 which are to be connected to a camera body,first information transfer means 101 for transmitting a first set ofinformation that is specific to the lens through a part of, or all ofthe electrical contact group 100, a second information transfer means102 for transmitting a plurality of variable information that isspecific to the lens through a memory means connected to the electricalcontact group 100 to the camera body, third a information transfer means103 for transmitting and receiving information to and from the camerabody 1 through an arithmetic/control means connected to the electricalcontact group, and, first and second switching means 104 and 105 forselecting the first information transfer means 101, the secondinformation transfer means 102 or the third information transfer means103, in accordance with the state of connection of the electricalcontact group 100 to the camera body 1.

The new camera body 1 of the present invention to which a lens isdetachably mounted comprises, as shown in FIG. 2, a group of electricalcontacts 200 provided on a camera body mount to which the photographiclens is mounted, determining means 201 for judging the type ofphotographic lens that is to be attached to a camera body in accordancewith the state of connection of the photographic lens to the electricalcontacts 200, first control means 202 for controlling the photographiclens in response to a first set of information which consists of a pairof information of the electrical contacts as a whole and whichrepresents a first type in which the photographic lens supplies only thefirst information to the camera body, second control means 203 forcontrolling the photographic lens in response to a plurality of a secondset of information which are specific to the photographic lens and whichrepresent a second type in which the photographic lens supplies thesecond information to the camera body through a memory means connectedto the electrical contact group, and third control means 204 forcontrolling the photographic lens in response to a third set ofinformation which represents a third type in which the photographic lenshas an arithmetic/control means connected to the electrical contactgroup in addition to the memory means and receives and transmits thethird set of information from and to the camera body.

FIG. 3 is a block diagram which outlines the new system which isstructured by a combination of the new lens 2 and new camera body 1 ofthe present invention.

The new camera body 1 is equipped with two CPUs: a main CPU 10 whichprocesses various information for photographing and a display CPU 11which is used to input information from switches and to exchange anddisplay information for the new lens 2. Besides the main CPU 10 anddisplay CPU 11, the new body 1 also includes an LCD panel 12 whichdisplays various information, a Dx code input circuit 13 where the ISOsensitivity of film is inputted with a Dx code which is printed on thefilm cartridge, a light receiver 14 which measures the brightness of asubject by an incident light beam through a photographic lens, an A/Dconverter 15 which converts analog signals of an output of the lightreceiver 14 into digital signals, an exposure control circuit 16 whichcontrols a shutter in accordance with various photographic conditions,an automatic focus change coupled device (AF CCD) 17 for detecting afocus condition which receives rays of a subject image formed by theincident light beam through the photographic lens, and a CCD processcircuit 18, which detects the focusing state of the photographic lens byan output of the AF CCD 17.

An auto focus (AF) motor 19 which serves to focus a lens, transfers adrive force to a conventional photographic lens through a coupler 19a(see FIGS. 3 and 4) which is provided on the mount portion when aconventional type photographic lens (which does not provide an AF motortherein) is mounted to the camera body 1. The main CPU 10 controls theamount of rotation of the AF motor 19 through an AF motor controlcircuit 20 according to the signal of the CCD process circuit 18 and thepulse signal of the AF pulser 21, which detects the amount of rotationof the AF motor 19.

A battery 22 supplies electric power to each active element in thecamera body described above, to a motor in a new photographic lens to bedescribed later, and to the CPUs.

On the other hand, a new lens 2 can house three motors (an AF motor 60,a power zoom (PZ) motor 61, and an automatic diaphragm (stop) control(AE) motor 62). The three motors allow an auto focus operation, a powerzoom operation, and a diaphragm control operation to be conducted withthe drive forces in the camera body.

The new lens 2 provides a conventional gear mechanism (or cam mechanism)which performs the focusing and zooming operations by relatively movingeach movable lens by rotating a focusing (cam) ring or a zooming camring. The AF motor 60 and PZ motor 61 rotate the individual cam rings.

Each motor is controlled by a lens CPU 66 that functions as a computingmeans (an arithmetic/control means) through AF motor drive section 63,PZ motor drive section 64, and AE motor drive section 65.

A lens ROM 67, which is a storage means for storing informationintrinsic to a lens, acts as an information input means to the lens CPU66. An Af pulser 68, PZ pulser 69, and AE pulser 70 converts the amountof driving force of each motor into pulses and detects the pulses. Azoom code plate 71 and distance code plate 72 detect a rotation positionof the zooming cam ring and focusing cam ring, respectively.

The code plate comprises a code plate which is fixed to a cam ring and aplurality of brushes which is in slidable contact with the code plate.The code plate detects an absolute rotating position of each cam ring bythe contact state of the brushes. The "code plate" includes such a codeplate and brush in this specification. FIG. 3 shows the code plate as ageneral term.

The lens CPU 66 is connected to the control sections and the input meansdescribed above. The lens CPU 66 can communicate with the new body 1through a set of electric contacts to be described below. For example,the lens CPU 66 has a function which receives the quantity (amount) ofdefocusing detected by the camera body, references data stored in theROM 67, computes the amount of drive force, detects the amount of driveforce by the AF pulser 68, and drives the AF motor 60; or a functionwhich detects the amount of drive force by the AE pulser 70 inaccordance with a stop number which is determined by the camera body androtates the AE motor 62.

The new lens 2 can include an AF coupler 73 which drives a focus lens sothat the AF motor of the camera body can perform the focusing operation.

STRUCTURE AND ARRANGEMENT OF ELECTRIC CONTACTS ON MOUNT

The structure of the mount portion which connects the new body 1 to thelens 2 is described, along with the position of the electric contacts.In this camera system, a bayonet mount system, which connects a lens anda body by engaging a plurality of contacts provided on both of the lensmount and the body mount, is described.

FIG. 4 shows a front view of the new camera body 1. On the lens mountopening, a mount ring 30 is fixed to the new camera body 1 with fivescrews 31a to 31e.

On the mount ring 30, a body side contact Fmax1 32, body side contactFmax2 33, body side contact Fmax3 34, body side contact Fmin1 35, bodyside contact Fmin2 36, and body side contact Cont 38 are provided, eachof which is insulated from the mount ring 30 and protrudes therefrom. Abody side contact A/M 37 is provided in such a manner that it does notprotruded is insulated from the ring 30 (see FIG. 6).

A body side contact V_(BATT) 40 and body side contact Vdd 41 areprovided inside the mount ring 30 (see FIG. 4).

Pin 42 is used to prevent a lens from rotating. The pin 42 is normallyprotruded by a spring force, and is inserted into an engagement hole ofthe lens, thereby prohibiting the lens thereon from rotating. By pushinga lever 43, the pin 42 is retracted into the mount ring 30 therebyallowing the lens to rotate for removal purposes.

As shown in FIG. 5, a mount ring 80 is fixed with five screws 81a to 81eto a mount portion of the new lens 2.

On the mount ring 80, a lens side contact Fmax1 82, lens side contactFmax2 83, lens side contact Fmax3 84, lens side contact Fmin1 85, andlens side contact Fmin2 86 are provided, each of which is insulated fromthe mount ring 80 and which do not protrude therefrom. A lens sidecontact Cont 87 and lens side contact A/M 88 are provided in such amanner that they protrude from the mount ring 80 while being insulatedfrom the ring 80 (see FIG. 7).

A lens side contact V_(BATT) 90 and a lens side contact Vdd 89 areprovided inside the mount ring 80.

An engagement hole 92, which prohibits the lens from rotating when thepin 42 is engaged, is provided on the mount ring 80. Also, the abovementioned AF coupler 73 is provided on the mount ring.

In the above contact arrangement, when the new lens 2 is mounted on thenew camera body 1, corresponding contacts are electrically connected.The protrusion and retraction setting of each contact is used fordistinguishing a combination state of a conventional camera system and anew camera system of the present invention, as will be described later.

In the above example, two set of contacts 39, 40 and 89, 90 are providedinside the mount ring. However, it is also possible to provide all thecontacts on or inside the mount ring.

NEW BODY CIRCUIT

A new camera body circuit is described below in accordance with moredetailed circuit diagrams.

FIG. 6 shows a circuit of the new camera body 1.

At terminal V_(DD1) of the display CPU 11, a voltage of battery 22 issupplied through a constant voltage regulator 23 which is backed up by asuper capacitor 24. The constant voltage is always suplied to terminalV_(DD1).

Terminal P1 of the display CPU 11 is connected to a DC/DC converter 25which turns on/off the power of the main CPU 10. Terminal P2 isconnected to a photometry switch SWS, which is turned on when a shutterbutton is depressed halfway. Terminal P3 is connected to a releaseswitch SWR which is turned on when the shutter button is fullydepressed. Terminal P4 is connected to a lock switch SWL, which isturned on so as to get ready for the camera to photograph. Data of eachswitch SWS, SWR and SWL is inputted to the display CPU 11 throughterminals P2, P3 and P4 respectively. While the lock switch SWL isturned on, when the photometry switch SWS or the release switch SWR isturned on and when data on the lens side is inputted to the main CPU 10,the DC/DC converter 25 supplies power to terminal V_(DD) of the main CPU10 by a command from the display CPU 11 that is sent to the DC/DCconverter 25.

Terminal P5 of the display CPU 11 is connected to a mode switch SWM,which selects a photographing mode, such as a programmed photographingmode, an automatic photographing mode, and a manual photographing mode.Terminal P6 is connected to a drive switch SWDr, which selects a drivemode, such as a single shot mode and continuous shot mode. Terminal P7is connected to an exposure compensation switch SWXv which allows anexposure to be compensated. When one of the switches SWM, SWDr and SWXvconnected to terminals P5, P6 and P7 are turned on, by operating anup-count switch SWUp connected to terminal P8 or a down-count switchSWDn which is connected to terminal P9, individual settings, changeableby the switches SWM, SWDr and SWXv can be changed.

A group of terminals P_(SEG) serves to operate an LCD panel 12. When thelock switch SWL is turned on, the LCD panel 12 displays variousphotographing data necessary through the set of terminals P_(SEG).

Terminal P10 of the display CPU 11 is connected to the body side contactFmax1 32; terminal P11 to the body side contact Fmax2 33; terminal P12to the body side contact Fmax3 34; terminal P13 to the body side contactFmin1 35; terminal P14 to the body side contact Fmin2 36; terminal P15to the body side contact A/M 37; terminal P16 to the body side contactCont 38; terminal P17 to the body side contact Vdd 39; terminal P18 to aswitch circuit 26.

In addition, the switch circuit 26 serves to switch between the bodyside contact V_(BATT) 40 and the battery 22 by a H (high)/L (low) signalstate of terminal P18. A body side contact Gnd 41 is connected to aground of the battery 22 along with terminal Gnd of the display CPU 11.

A body side contact Gnd 41 is electrically connected to the mount ring30.

The display CPU 11 and the main CPU 10 transfer data between each othercomprising 8-bit command codes, as listed in TABLE 1, through a serialclock terminal SCK, serial-in terminal SI, and serial-out terminal SO.

In TABLE 1, codes 0 to 3, which are outputted from the display CPU 11 tothe main CPU 10, are set depending on the conditions of switchesprovided on the new body, and data of the lens ROM and lens CPU. Codes 4to 7 are data being inputted to the display CPU from the main CPU andare set in accordance with measured data by a photometer, a objectdistance measuring device, and so forth under control of the main CPU10.

A group of PA contacts of the main CPU 10 is connected to an A/D circuit15 for photometry; a group of PB contacts to an exposure control circuit16; a group of PC contacts to the CCD process circuit 20 18; a group ofPD contacts to the AF motor control circuit; a group of PE contacts tothe AF pulser 21; and a group of PF contacts to the Dx input circuit 13.In addition, the A/D circuit 15 is connected to an light receiver 14;the CCD process circuit 18 to the AF CCD 17; the AF motor controlcircuit 20 to the AF motor 19 in the camera body, as described above.

Terminal P20 of the main CPU 10 is connected to a first AF switchSW_(AF1) which switches between an automatic mode (to drive a focusingoperation by the AF motor 19) and a manual mode where the user manuallyperforms the focusing operation. Terminal P21 is connected to a secondAF switch SW_(AF2) which switches between a focusing priority mode and arelease priority mode for a shutter release operation. The first AFswitch SW_(AF1) is mechanically interlocked with the second AF switch sothat when the first AF switch is placed in the manual mode, the secondAF switch SW_(AF1) is set to the release priority mode.

ELECTRIC CIRCUIT OF NEW LENS

FIG. 7 shows a circuit of the new lens 2. The lens side contact V_(BATT)90 is connected to motor drive sections 63, 64 and 65. By switchingamong these drive sections 63, 64 and 65, power is directly supplied tothe motors 60, 61 or 62 through the contact V_(BATT) 90 from the battery22 in the camera body. The motor drive sections 63, 64 and 65 areconnected to terminals PH, PI and PJ of the lens CPU 66, respectively,so as to control them. Pulsers 68, 69 and 70 are connected to terminalsP20, P21 and P22, respectively, thereby determining the driving amountof each motor being detected, which is inputted to the lens CPU 66.

The lens side contact Vdd 89 supplies power from the body side displayCPU 11 to terminal Vdd of the lens CPU 66, and a reset circuit,comprising resistor R, diode D and capacitor C.

The reset circuit has a specific time constant determined by theresistor R and capacitor C. When the power supply voltage has stabilizedafter Vdd is applied and a specific time period corresponding to thetime constant elapses, the reset circuit causes the signal state atterminal RESET of the lens CPU 66 to change from active (L) to inactive(H) and the program of the lens CPU 66 to be started.

This lens CPU 66 controls each motor driving section in the lens inaccordance with information sent from lens ROM 60 that is transferredfrom the body and transfers set data to the camera body. Data, listed inTABLE 2, is set in a RAM section of the lens CPU 66 which functions as athird information transfer means. Addresses 0 to 3 of the lens CPU 66are set by the lens CPU 66 with the state of the lens side switches,data of lens ROM, and input data from the pulsers. Addresses 4 to 7 areset in accordance with data being inputted from the body side main CPU10 through the display CPU 11.

In addition, addresses 1 to 4 of the lens CPU 66 are an area whichstores data for determining the number of drive pulses (K value, Kval)for a focusing lens per image surface moving unit which varies dependingon the focal length. This data is computed by data of the lens ROM 67and outputted from the PZ pulser and zoom code plate.

In conventional zoom lenses, Kval is determined by length data of a zoomcode range in a lens ROM which is addressed by the zoom code plate. Inthe new lens 2, the area of the same zoom code range can be divided intomore smaller steps to generate more by PZ pulses which are outputtedfrom the PZ pulsers than the conventional zoom lenses do, therebyeffecting a more precise AF control.

Terminals P23 to P27 of the lens CPU 23 are provided on the lens;terminal P23 is connected to a third AF switch SW_(AF3), which switchesbetween an automatic mode and a manual mode of the auto focus operation;terminal P24 to a zoom selection switch SW_(PZ1), which selects betweena motor drive mode and a manual mode of the zooming operation; terminalP25 to an image magnification switch SW_(PZ2), which serves toautomatically perform the zooming operation depending on a relativemovement to a subject so as to keep the image magnification thereofconstant; terminal P26 to a Far side zoom switch SW_(PZF), which causesthe PZ motor 69 to move the photographic lens in the direction where thefocal length thereof increases; terminal P27 to a Near side power zoomswitch SW_(PZN) which causes the PZ motor 69 to move the lens in thedirection where the focal length thereof decreases.

The lens CPU 66 includes a terminal INT wherein electric signalsinterrupt an execution of a software program; terminal SCK where aserial clock from the body side display CPU 11 is inputted; terminalSI/SO which transfers serial data; and terminal RDY which synchronizes aserial communication of the lens CPU 66 with peripheral devices.

The terminal INT allows an interrupt of the lens CPU 66 to be enabledwhen the signal state thereof is changed from L to H after the resetoperation. When the serial communication is enabled, the signal state ofterminal RDY is changed to L and the communication enable state isinformed to the camera body display CPU 11.

In addition, the zoom code plate 71 is connected to terminals PK of thelens CPU 66 and terminals PL of the lens ROM 67. The distance code plate72 is connected to set of terminals PM of the lens ROM, whereby focallength information and object distance information corresponding to theactual lens conditions are input.

The lens ROM 67 stores information intrinsic to the photographic lens,such as a minimum F number, maximum F number, and amount of change of Fnumber caused by the zooming operation. The lens ROM 67 outputs dataunder control of the lens CPU 66 or camera body CPU 10. As described inthe example, the high order addresses of the lens ROM are assigned inaccordance with the zoom code detected from the zoom code plate. On theother hand, the low order addresses are assigned by counting clockpulses inputted from terminal SCK.

The lens ROM 67 structure comprises a second information transfer means.

The lens side Fmax1 contact 82 is connected to terminal RESET of thelens ROM 67 and terminal INT of the lens CPU 66. The lens side contactFmax2 83 is connected to the lens ROM 67 and terminal SCK of the lensCPU 66. The lens side contact Fmax3 84 is connected to terminal SO ofthe lens ROM 67 and terminal SI/SO of the lens CPU 66. The lens sidecontact Fmin1 85 is connected to terminal RDY of the lens CPU 66.

Contacts 82 to 85 are also connected to the emitters of PNP transistorsTr1 to Tr4. The bases of the PNP transistors Tr1 to Tr4 are selectivelyconnected to contact Cont 87 or the emitter of the respective transferthrough a fuse terminal (not labelled, see FIG. 7). The collectors ofthe PNP transistors Tr1 to Tr4 are connected to the contact Gnd 91. Itis also possible to provide the fuses between the emitters and thecontacts 82 to 85.

While a voltage is applied to each contact 82 to 85, when the potentialof the contact Cont 87 equals that of the contact Gnd, each transistoris turned on, so that the contacts Fmax1, Fmax3, and Fmin1, which are inthe connection state go L (low level) and the contact Fmax2 which is inthe no-connection state goes H (high level). In other words, itfunctions as one memeory cell of a ROM provided to each contact 82 to85. Therefore, by connecting the fuse which is connected to the base ofeach transistor to the contact Cont 87 or emitter, one bit ofinformation can be stored to each contact 82 to 85. It is also possibleto provide these transistors in the lens ROM 67.

The lens side contact Cont 87 is connected to terminal Vc of the lensROM 67 which supplies electrical power to the lens ROM 67 from camerabody. When the power is supplied, the lens ROM functions.

The lens side contact A/M 88 is connected to a line with a groundpotential connected to the lens side contact Gnd 91 through a diaphragmchanging switch SWA/M, which is switched between an automatic mode and amanual mode of the operation by turning the diaphragm ring on the lens.

The lens side contact Fmin2 86 is grounded through a fuse 74 as a fixedinformation section which is the same as that provided in a conventionalAE lens, described later. Depending on whether the fuse is present orabsent, one bit of fixed information is transferred to the camera body.The lens side contact Fmin2 86, contact Fmax1 82 to Fmax3 84, andcontact Fmin1 85 provide data as listed in TABLES 9 to 11, whichstructure a first information transfer means.

The lens side contact Gnd 91 is electrically connected to the mount ring80. When the lens is mounted on the camera, the contact 91 iselectrically connected to the mount ring 30 of the body.

COMBINATION OF NEW SYSTEM AND CONVENTIONAL SYSTEM

Combinations of the new lens, new body, conventional type lens, andconventional type body are described below.

FIG. 8 illustrates a block diagram wherein an AEAF (Auto Exposure AutoFocus) lens 3 which provides a conventional auto focus function ismounted on the new camera body 1.

The AEAF lens 3 provides a lens ROM 67 and an AF coupler 73 which drivesa lens for the focusing operation by the AF motor 19 in the camera body.

In addition, as shown in FIG. 9, the AEAF lens 3 provides lens sidecontacts Fmax1 82 to Fmax3 84, which transfer a minimum F number as a3-bit information when a terminal Cont 87 is grounded; a firstinformation transfer means consisting of contacts Fmin1 85 and Fmin2 86which transfer a maximum F number as a 2-bit information; and a secondinformation transfer means including the lens ROM 67 which can read databy the new body or the conventional type AEAF body CPU with the AEAFfunction. The arrangement of the contacts is shown in FIG. 10.

When the AEAF lens 3 is mounted on the new body 1, except for twocontacts of the new body 1, namely, contact Vdd 39 and contact V_(BATT)40, the corresponding contacts of lens side and body side are connectedto each other and the camera body can receive the second informationthat the lens ROM stores.

A conventional AEAF body equipped with an auto focus function and autoexposure function does not provide the Vdd and V_(BATT) contacts, asshown in FIG. 11, unlike the new body. Since the AEAF body is the sameas the new body at least in the electric circuit diagram except that theformer camera body does not need the switch circuit connected to theV_(BATT) contact, the drawing of the AEAF body is omitted.

When the new lens 2 is mounted on the conventional AEAF body, the bodydoes not provide the Vdd contact and V_(BATT) contact, and the lens CPUand each motor driving section in the lens do not function. However,because the AF coupler of the body is connected to that of the lens, thesame operations as the conventional AEAF system can be performed. Inaddition, data of the lens ROM can be transferred to the body.

FIG. 12 is a circuit diagram of a conventional AE body which providesonly an AE function. This AE body provides the contacts Fmax1 32 toFmax3 34, contacts Fmin1 35 and Fmin2 36, and contact A/M 38. When thenew lens 2 is mounted on such an AE body, a contact Cont, which isprotrudes from the mount ring of the body touches a mount ring of thebody. Thus, the electrical is equal to that of the potential of thecontact Cont 87 ground. When a voltage is applied to each contact, thecontacts Fmax1, Fmax3, and Fmin2 go L and the contact Fmax2 goes H,thereby information of minimum F value F_(NO) =2.0 and maximum F_(NO)=22 listed in TABLES 9 and 10 are provided.

FIG. 13 shows a circuit of an AE lens which only provides the AEfunction. In this lens, each contact provides one bit of information.Between contact A/M 87 and the ground potential, a diaphragm selectionswitch SWA/M is connected. To other contacts, fuses (not labelled) whichprovide fixed information are provided. When this AE lens is mounted onthe new body 1, a minimum F number, a maximum F number, and informationrelating to switching between an automatic mode and a manual mode of adiaphragm operation are transferred to the body through the contactsFmax1 82 to Fmax3 84, Fmin1 85, Fmin2 86 and A/M 88.

FLOWCHART OF NEW SYSTEM

Referring to FIG. 14 to the operation of the new system, constructed asabove, is described. In the following description, each program of thedisplay CPU 11, main CPU 10, and lens CPU 66 is separately described.

FIG. 14 shows a timer routine of the display CPU 11.

The display CPU 11 detects whether the lock switch state is ON or OFF insteps 1 and 2 (termed S. 1 and S. 2, hereinafter and in the drawings).When the lock switch is turned OFF, a switch interrupt is prohibited andturns off the power of the LCD panel 12 in S. 3 and S. 4; and waitsuntil the lock switch SWL is turned ON while performing the timerroutine in a period of 125 ms in S. 5 to S. 6 of the timer process.

When the lock switch is turned ON, the display CPU 11 detects the typeof lens being mounted by calling a data input subroutine shown in FIG.15 in S. 8 and also detects whether the auto focus mode has beenselected by calling an AF determination process subroutine shown in FIG.17 in S. 9.

The data input subroutine causes each port which is used forcommunication with the lens to enter the input mode in S. 30 and detectthe level of contact Cont 38 in S. 31 and S. 32. When the lens does notprovide the contact Cont, namely, when the AE lens is mounted, since thecontact Cont 37 of the body touches the mount ring, the ground leveltakes place (namely, L). Consequently, this subroutine reads the minimumF number, the maximum F number, and the stop A/M switching state as a6-bit parallel data in S. 33, sets flag F_(AE), which represents thatthe lens being mounted is an AE lens in S. 34, and returns to the timerroutine.

When contact Cont is high (H) level, the data input subroutine causesthe signal level to be changed to the low (L) level in S. 35 and detectsthe signal levels of other contacts in S. 36 and S. 37. When the signallevels of all the contacts being detected are high (H), this subroutinedetermines that the lens is not mounted, sets flag F_(NO), whichrepresents that the lens has not been mounted in S. 38, and then returnsto the timer subroutine.

The decision in S. 37 is negated when the new lens, or an AEAF lens, hasbeen mounted. Then, the signal level of contact Cont is changed to high(H) in S. 39 and detects the signal level of the other contacts in areinputted S. 40 and 41. When the signal levels of all the contacts beingdetected are not high (H), the data input routine determines that thelens CPU, the lens ROM or the lens is defective, sets flag F_(NO) to 1which represents that the lens has not be mounted in S. 38, and returnsto the timer routine.

When the data input routine determines that the signal levels of all thecontacts are high in S. 41, it means that a lens which has a lens CPU orlens ROM has been mounted. Thereafter power is supplied to the lens CPUin S. 42 to S. 44, the mode for the contacts Fmax1 to Fmax3 is changedfrom the port mode to the serial communication mode in S. 45, and a waitoccurs unitil the lens CPU becomes ready to communicate in S. 46.

When the lens CPU becomes ready to communicate, this routine sends anaddress of the lens CPU in S. 47 and after the lens CPU becomes ready tocommunicate again, it inputs data of the lens CPU in S. 49. This routinedetects the 2/3 code of bits 5 to 7 of address 0 of the lens CPU at S.50 and when it is OK, sets flag F_(CPU) to 1, which represents that thelens CPU is provided in S. 51. The 2/3 code is a code where 2 of 3 bitsis set to "1" as listed in TABLE 3. This code serves to distinguishwhether the lens being mounted has a lens CPU.

In S. 52 and S. 53, the routine causes the signal state of the contactFmax1 to go low (L) and inputs data of the lens ROM. When F_(CPU) is"1", processing returns to the display timer CPU routine. When F_(CPU)is 0, detects the 2/5 code of bits 3 to 7 of address 0, and when it isOK, sets flag F_(ROM) which represents that the lens is not mountedto 1. When it is not OK, flag F_(NO), which represents that the lens isnot mounted, is set to 1 before processing and returns to the timerroutine (S. 54 to S. 57).

FIG. 16 shows a timing chart of the data input process described above,wherein FIG. 16(a) represents that the AEAF lens which has a lens ROM,is mounted. In this case, the routine detects the signal level of thecontact Cont at t1 (S. 31), changes the signal level of terminal P10 toL at t2 (S. 52), and reads data of the lens ROM from t3 (S. 53).

FIG. 16(b) shows a data input process with a new lens which provides thelens CPU. In this case, at t1 this process performs the same operationas the above subroutine does. However, at t2 the process changes thesignal level of the contact Cont to low and inputs the signal level ofeach contact (S. 36). When they are not all H at t3, the signal level ofthe contact Cont is changed to H (S. 39). When all the signal levels ofterminals P10 to P13 and P17 are H, the process changes the signal stateof the contact Fmax1 to L, and the contact Vdd to H at t4 (S. 42 and S.43). At t5 the signal level of the contact Fmax1 is changed to H (S.44). At t6 when the signal level of the contact Fmin1 is L at t7 (S.46), at t7 the process starts a serial communication process is startedat t7 (S. 47).

FIG. 17 shows the AF determination subroutine which is called in S. 9 ofthe timer subroutine. First, the subroutine determines which type oflens is mounted by a flag being set in the data input process describedabove and performs a process corresponding to the lens being mounted inS. 60 and S. 61. When the lens has a the lens CPU, the subroutinereferences address 0 bit 3 of the lens CPU in S. 62. This bit is set bythe lens CPU when the third AF switch position is changed. When theswitch position is "1", the subroutine further detects the switch stateof the first AF switch of the body in S. 63. When the state of bothswitches are ON, the subroutine sets flag F_(AF) to 1 so as to indicatethat the auto focus mode takes place in S. 64. When the state of one ofthe switches is OFF, the subroutine clears the flag F_(AF) so as toindicate that the manual focus mode takes place (S. 65).

On the other hand, when an AEAF lens which has a lens ROM is mounted,the first AF switch of the body determines whether the auto mode ormanual mode takes place. When an AE lens which does not have both a lensCPU and lens ROM is mounted, the manual focus mode is set.

After the process of the above subroutine is completed, when returningback to the timer routine, the display CPU 11 permits a switch interruptin S. 10 and causes the LCD panel to indicate the AF set statecorresponding to the flag state described above.

While a lens which provides a lens CPU is mounted, when the lens issuesa power hold request in S. 14 and S. 15, the timer routine changes thesignal state of P1 to L and starts the main CPU 10 at S. 16.

In S. 17 to S. 24, when the mode switch, drive switch, exposurecompensation switch, and up switch and down switch are provided andoperated, a process which changes the operation mode and displayindication thereof is conducted.

When such switches are not operated, the processes from S. 5 to S. 7 areconducted and the process end.

While the timer routine allows "SWS and R interrupt", when thephotometry switch and release switch are turned on, an interrupt processshown in FIG. 18 is executed.

In the SWS and R interrupt process, the process prohibits a further SWSand R interrupt in S. 70, turns on the power of the main CPU, andpermits a serial interrupt subroutine in S. 72.

The serial interrupt subroutine comprises two steps, which are shown inFIG. 19. The first step performs a command input operation in S. 90.Then, a related process operation is performed in S. 91. This subroutineserves to communicate with the main CPU in accordance with command codeslisted in TABLE 1 so as to conduct a required process.

When the lock switch SWL and the photometry switch SWS are turned ON,the SWS and R interrupt process repeats the steps in S. 73 to S. 78, soas to input information that changes from time to time and to performthe set change process for the mode, drive, and exposure compensation.These steps are the same as those conducted in steps S. 17 to 24 of thetimer routine.

When either the lock switch SWL or the photometry switch SWS is turnedOFF, the interrupt process subroutine turns OFF the power to the mainCPU, sets the timer, permits a timer interrupt, and executes the stepsin S. 79 to S. 82.

Referring to FIG. 20 to FIG. 22, the program installed in the main CPU10 will be described.

When the DC/DC converter 25 is turned on and power of the main CPU isturned ON, the main CPU is initialized in S. 100 and a determination ismade as to whether the photometry switch SWS or the release switch SWRis turned ON in S. 101.

When switches, SWS and SWR, are turned OFF the program reads a commandcode "1" transferred from the display CPU 11 and determines whether thelens has issued a power hold request based upon the state of address 0bit 4 of the lens CPU. When the lens does not issue the power holdrequest, the main CPU requests the display CPU 11 to turn OFF the powerhold in S. 104 and terminates the process. When the lens issues thepower hold request, the program sets bit 1 of command code 5 to "1" andtransfers it to the display CPU 11 in S. 105. Consequently, the displayCPU receives the data, sets P18 to H, turns on the switch circuit, andthen turns ON the power V_(BATT) of the motor driving section of thelens.

When the photometry switch SWS or the release switch SWR is turned ON,the program transfers a command which requests the display CPU 11 toturn ON the power to the lens CPU. Photometry A/D data is inputted,along with the DX code information data provided by the lens, theshutter speed set by the body, and the diaphragm value from the displayCPU in S. 107 to S. 109 so as to compute Tv (Time Value) and Av(Aperture Value) in S. 110.

The main CPU 10 transfers the computed information of Tv and Av to thedisplay CPU 11 so as to display them on the LCD panel 12.

The program determines whether the release switch SWR is turned ON in S.117. When the release switch is turned ON, and the AF is in the manualstate or the release priority mode is performed, control advances to S.138, described below, so as to conduct a release process. When therelease switch SWR is turned OFF or when it is turned ON while the AF isin the auto mode and the focusing priority mode is performed, theprogram causes the distance measuring process to start.

The main CPU 10 computes the quantity of defocus by inputting CCD data,determining the focusing state from the data and indicates the result inthe viewfinder in S. 115 to S. 117.

When a subject is not focused, the program advances from S. 118 to S.123, to be described later, so as to perform an AF process. When theamount of defocusing length is "0" in the focusing priority mode, theprogram performs a focus lock operation when the release switch SWR isturned ON while the photometry switch SWS is turned ON in S. 120 and S.121.

In the release priority mode with the switch SW_(AF2) is on, when therelease switch SWR is turned ON, the program advances from S. 122 to S.138. When the release switch SWR is turned OFF, the program advances theprocess to "A" (S. 123) rather than activating the release lockoperation.

FIG. 21 illustrates an AF process of the main flow of the main CPU.

When focusing is in the manual mode, the program returns back to S. 101so as to continue the process rather than driving the lens (S. 122). Inthe manual mode, the release priority mode automatically takes place.Thus, when the subject is not focused while the photometry switch SWS isturned ON and the release switch SWR is turned OFF, the programcontinuously executes the process in a loop until it determines that therelease switch SWR is turned ON in S. 112. When the release switch SWRis turned ON, the program goes from S. 113 to S. 138 so as to performthe release process. When the object is focused by manually operatingthe lens, the program may exit from S. 119 and S. 122 to "S. 138".

When the focusing is in the auto mode, the program selects one of fivelens drive methods depending on the performance of a CPU that mounted onthe lens, as described below.

The first case (combination) is that a conventional AEAF lens, whichprovides a lens ROM is mounted. In this case, like the conventionalmethod, the main CPU in the body computes drive pulses by the amount ofdefocusing length in S. 125 and the AF motor of the body drives the lensin S. 127 to S. 129.

The second and third cases (combinations) are that although a lensprovides a lens CPU, its performance is not so high. In this case, theprogram advances from S. 130 to S. 125 so that the main CPU in the bodycomputes the number of pulses depending on the amount of defocusinglength. After that, the program selects whether to drive the focusinglens by a motor in the lens side or by a motor in the camera body sidein S. 132.

In the second case, the AF motor in the body drives the focusing lens.Consequently, like the first case, the program performs the processes inS. 127 to S. 129.

In the third case, since the focusing lens is driven by a AF motorprovided in the lens, the lens CPU drives the AF motor in accordancewith the number of pulses transferred in S. 131. The main CPU waitsuntil the lens movement completion information is transferred from thelens CPU in S. 133 and S. 134 and after that, the program advances to"S. 101".

When the AF motor in the body drives the focusing lens, it is notnecessary to transfer the number of pulses for AF to the lens. However,the program transfers the number of pulses to the lens CPU in S. 131,which computes the image magnification using the amount of moving lengthof the focusing lens for performing a constant image magnificationcontrol operation. The constant image magnification control operationvaries the magnification of the lens so that the size of a subject imageon a film is maintained constant. This operation is conducted in themanner that the program detects a change of the magnification by theamount of defocus after the subject, which has been focused, movesconverting the change of magnification into a power zoom (PZ) motordrive pulses, and control the PZ motor.

The fourth and fifth cases (combinations) are that a very highperformance lens is being mounted to the camera body. In these cases,the lens CPU requests data of the amount of defocusing length. Even inthe conventional system, although a program which compensates anon-linear characteristics between the amount of defocus and the amountof driving length of lens has been installed, the system readscompensation data in a lens ROM and causes a CPU in the body to computethe compensation. Consequently, the CPU should have a general purposefunction. On the contrary, in the fourth and fifth cases, when the lensCPU converts the amount of defocus into pulses, even for a lens withmuch complicated linearity, suitable conversion can be performed,resulting in a more precise AF control operation than the conventionalsystem.

In the fourth case, the program inputs the number of drive pulsescomputed by the lens CPU to the main CPU in S. 137, so as to drive theAF motor in the body.

In the fifth case, since the program drives the AF motor in the lens inaccordance with drive pulses computed by the lens CPU, the main CPUwaits until the lens moving operation is completed in S. 133 and S. 134;the program returns back to "C" S. 101 and then continues the process.

FIG. 22 shows a release process of the main CPU main flow.

When the program advances from the main flow of the main CPU shown inFIG. 20 to steps S. 138 shown in FIG. 22, only while a lens which doesnot provide a lens CPU is employed, the program controls the diaphragmand the shutter speed in the body so as to perform the exposureoperation. When a lens which provides a lens CPU is employed, theprogram determines whether to perform the diaphragm control in the lensor from the body by data of the lens ROM. When the diaphragm control isperformed in the lens, the program transfers the number of steps of theAE stop-down operation computed by the main CPU to the lens CPU, issuesa stop-down start command and performs the exposure operation with theshutter speed controled by body side.

After the exposure operation is completed, the program causes the mainCPU to drive the wind motor for winding the film in S. 144. When driveC, namely, the continuous shot mode takes place, the program immediatelyadvances to S. 101, shown in FIG. 20, so as to continue the process.When the single shot mode takes place, the program waits until therelease switch is turned OFF in S. 146 and returns back to "S. 101".

Referring to FIGS. 23 and 24, the operation of the lens CPU isdescribed.

FIG. 23 is a main flowchart of the lens CPU. After the contact goes H bya command from the display CPU, the reset circuit operates and the resetoperation is released, resulting in the activation of the lens CPU.

The program initializes the lens CPU in S. 200, reads the status of eachswitch and the zoom code plate provided in the lens in S. 201 and S.202, and stores it in a RAM.

The program sets the terminal SI/SO to the serial input mode in S. 203to S. 205, so as to permit a serial interrupt, and sets the contact RDY(NOT RDY) to 1, so as to inform the display CPU that the serialcommunication is enabled.

The program sets a timer so as to continue this process at an intervalof 125 ms in S. 206 to S. 208 and completes the process one time.

FIG. 24 shows a flowchart of the serial interrupt process of the lensCPU which is executed when a serial interrupt from the display CPU ofthe camera body occurs.

The program sets the signal level of the contact RDY to H in S. 210,which informs the display CPU that the serial communication is disabled,determines which address of the lens CPU in TABLE 2 accords with thesignal being transferred from the display CPU and executes the processcorresponding to the address in S. 211.

When the program determines that the signal accords with Address 0 to 3,it outputs this data in serial in form S. 213 and S. 214. This data isset by the lens CPU in accordance with data of the switches and data ofthe lens ROM. After the data is outputted, the program sets the signallevel of the contact RDY to L, changes the port which was changed to theoutput mode in S. 216 and S. 217 to the input mode, permits a serialinterrupt, and returns back to the main flow so as to continue theprocess.

When the program determines that the signal accords with Address 5 to 7,it changes the contact SI/SO to the input mode in S. 219 and S. 220 soas to represent that the communication is enabled, inputs data in S.221, and advances to S. 216. This data is transferred to the lens CPUfrom the main CPU through the display CPU.

When the program determines that the signal does not accord with Address0 to 3, Address 5 to 7 and Address 4, namely Add 1 to 4 or an addresswhich is not permitted is specified, it advances to S. 216 where nopractical process is conducted before returning back to the main flow.

When data transferred from the display CPU accords with address 4 of thelens CPU, a process in accordance with the bit is conducted. When bit 7is "1", the program drives the PZ motor to perform the zooming operationand sets the moving completion bit in S. 224 to S. 227. When bit 6 is"1", the program drives the AF motor for performing the focusingoperation and sets the moving completion bit in S. 229 to S. 232. Whenbit 5 is "1", the program drives the AE motor for performing thestop-down operation.

After the process of each motor is completed, the program advances to S.216 and S. 217 before returning to the main flow so as to perform theprocess.

The operations of the three CPUs included in the new system have nowbeen described.

As described above, the camera system of the present inventiondetermines which type of lens is mounted on a camera body and inputsthree kinds of data depending on the performance of the lens.Conversely, the lens supplies three steps of information depending onthe performance of the camera body.

In addition, when a new camera body and new lens (both of which relateto the present invention) are combined, by connecting the control meansof the body and that of the lens, more precise information can betransferred than conventional camera systems. For example, a moreprecise AF control operation is available.

                  TABLE 1                                                         ______________________________________                                        (Command Codes)                                                               bit                                                                           Code 7      6       5    4     3    2     1    0                              ______________________________________                                        0    Mode       Drive      Exposure compensation                              1    Lens CPU Add 0 to 3                                                      2    Lens ROM Add 0 to 7                                                      3    T.sub.v being set A.sub.v being set                                      4    T.sub.v to be displayed                                                                         A.sub.v to be displayed                                5    ISO                          V.sub.Batt                                                                         PH                                                                       ON   request                                6    Number of film shots Winding information                                 7    Lens CPU Add 4 to 7                                                      ______________________________________                                    

                                      TABLE 2                                     __________________________________________________________________________    (L-CPU)                                                                       bit                                                                           Address                                                                            7   6   5     4   3   2  1    0                                          __________________________________________________________________________    0    2/3 code      PH  AF  PZ      Lens                                                          request                                                                           A/M A/M     O/C                                        1    Short focal length data                                                  2    Long focal length data                                                   3    Sf end                                                                            Lf end                                                                            AF    AF  PZ F                                                                              PZ S                                                                             PZ move                                                                            AF move                                                 N end F end      complete                                                                           complete                                   4    PZ  AF  AE                                                                    start                                                                             start                                                                             stop-down                                                        5    Amount of focal length (number of pulses)                                6    Amount of defocusing length (number of pulses)                           7    Number of AE stop-down steps (number of pulses)                          01   Number of start pulses in zoom code plate range                                                        Ph                                              02   Pulse width in zoom code plate range                                                                   Pw                                              03   Start Kval               Ka                                              04   Kval calibration coefficient                                                                           Kc                                              __________________________________________________________________________

                  TABLE 3                                                         ______________________________________                                        Add 0 2/3 code                                                                bit      7     6          5                                                   ______________________________________                                               1   1          0     RAM ver. 1                                               1   0          1     RAM ver. 2                                               0   1          1     RAM ver. 3                                        ______________________________________                                    

                  TABLE 4                                                         ______________________________________                                        (L-ROM)                                                                       bit                                                                           Add     7     6       5   4     3   2     1   0                               ______________________________________                                        0       2/5 code                                                              1       Lens data                                                             2       Kvalue data                                                           3       AF compensation amount data                                           4       Release Av  Minimum Av                                                5       Exposure compensation amount data                                     6       Focal length data                                                     7       Distance code data                                                    ______________________________________                                    

                  TABLE 5                                                         ______________________________________                                        Add 0 bit                                                                     7       6     5         4   3       2/5 code                                  ______________________________________                                        0       0     0         1   1       Single lens                               0       0     1         0   1       Zoom lens                                 0       0     1         1   0       Macro lens                                ______________________________________                                    

                  TABLE 6                                                         ______________________________________                                        Add 0 bit 2,1                                                                 bit           bit                                                             ______________________________________                                        0             0     ROM ver. 1                                                0             1     ROM ver. 2                                                1             0     ROM ver. 3                                                1             1     ROM ver. 4                                                ______________________________________                                    

                  TABLE 7                                                         ______________________________________                                        Add 0 bit 0                                                                   ______________________________________                                                0      Input mode                                                             1      Input/output mode                                              ______________________________________                                    

                  TABLE 8                                                         ______________________________________                                        Add 2                                                                                bit                                                                    ______________________________________                                               0       AF presence/absence                                                   1       AE presence/absence                                                   2       PZ presence/absence                                                   3       AF drive type                                                         4       AF data request                                                       5       Pulse request                                                         6       Defocus request                                                       7       AE drive type                                                  ______________________________________                                    

                  TABLE 9                                                         ______________________________________                                        Minimum F.sub.NO information                                                         Fmin                                                                   F.sub.NO 3              2     1                                               ______________________________________                                        1.4      0              0     0                                               1.7      0              0     1                                               2        0              1     0                                               2.5      0              1     1                                               2.8      1              0     0                                               3.5      1              0     1                                               4        1              1     0                                               4.5      1              1     1                                               ______________________________________                                    

                  TABLE 10                                                        ______________________________________                                        Maximum F.sub.NO information                                                                 Fmax                                                           F.sub.NO         2     1                                                      ______________________________________                                        22               0     0                                                      32               0     1                                                      45               1     0                                                      ______________________________________                                    

                  TABLE 11                                                        ______________________________________                                        A/M             0      0                                                      ______________________________________                                        Lens            Auto   Manu                                                   ______________________________________                                    

I claim:
 1. A photographic lens detachably mounted to a camera body,comprising:a group of electrical contacts which are selectivelyconnected to said camera body; first information transfer means fortransmitting a first set of information peculiar to said lens through atleast a part of said electrical contact group; second informationtransfer means for transmitting a plurality of variable informationpeculiar to said lens through memory means connected to said electricalcontact group to said camera body; third information transfer means fortransmitting and receiving information to and from said camera bodythrough an arithmetic/control means connected said electrical contactgroup; and switching means for selecting said first information transfermeans, second information transfer means or third information transfermeans, based on the electrical connection of said electrical contactgroup to said camera body.
 2. A photographic lens according to claim 1,wherein said switching means comprises a first switching means forselecting said first information transfer means or said secondinformation transfer means and said third information transfer means,based on said electrical connection of said electrical contact group tosaid camera body, and a second switching means for selecting either saidsecond information transfer means or said third information transfermeans when said first switching means selects said information transfermeans and said third information transfer means.
 3. A photographic lensaccording to claim 1, wherein said first set of information peculiar tosaid lens includes information on a maximum F Value data of said lens, aminimum F Value data of said lens, and auto/manual switching data of adiaphragm.
 4. A photographic lens according to claim 1, wherein saidvariable information includes information on a maximum F value, minimumF value, focal length, forward displacement of a focusing lens, and adefocus coefficient.
 5. A photographic lens according to claim 4,wherein said third information transfer means transmits said variableinformation to said camera body and receives defocus data and diaphragmdata from said camera body.
 6. A photographic lens according to claim 1,further comprising a focus adjusting mechanism which controls a focalpoint and a focus control means for driving said focus adjustingmechanism.
 7. A photographic lens according to claim 6, wherein saidarithmetic/control means actuates said focus control means in accordancewith defocus data inputted from said camera body through said thirdinformation transfer means.
 8. A photographic lens according to claim 6,further comprising an association mechanism which is connected to afocus adjusting mechanism driving means provided on said camera body todrive said focus adjusting mechanism.
 9. A photographic lens accordingto claim 8, wherein said focus adjusting mechanism is driven throughsaid association mechanism when said information transfer means isselected.
 10. A photographic lens according to claim 8, wherein saidarithmetic/control means arithmetically detects the displacement of thedrive of said focus adjusting mechanism driving means on said camerabody in accordance with defocus data supplied by an object distancemeasuring means provided on said camera body through said thirdinformation transfer means and a defocus coefficient data stored in saidmemory means to send displacement data of the drive of said focusadjusting mechanism driving means to said camera body through said thirdinformation transfer means, so that said focus adjusting mechanism isdriven by said focus adjusting mechanism driving means which operates inresponse to said displacement data through said association mechanism.11. A photographic lens according to claim 1, further comprising adiaphragm mechanism which actuates a diaphragm, a diaphragm controlmeans for driving said diaphragm mechanism, and a diaphragm associationmechanism which transmits a drive force of a diaphragm driving mechanismprovided on said camera body to said diaphragm mechanism.
 12. Aphotographic lens according to claim 11, wherein said arithmetic/controlmeans actuates said diaphragm control means in accordance with diaphragmdata inputted from said camera body through said third informationtransfer means when said third information transfer means is selected.13. A photographic lens according to claim 11, wherein said diaphragmmechanism is driven by said diaphragm driving mechanism provided on saidcamera body when said first information transfer means or said secondinformation transfer means is selected.
 14. A photographic lensaccording to claim 1, further comprising a power zoom means, a focallength detecting means for detecting a focal length of said lens, and adetecting means for detecting forward displacement of a focus lens,wherein said arithmetic/control means receives in-focus data from saidcamera body when said third information transfer means is selected todetect a magnification based on the said forward displacement detectingmeans and the data of said focal length detecting means, whereby saidpower zoom means is actuated in accordance with defocus data sent fromsaid camera body in a direction in which the magnification of an imageis maintained constant.
 15. A photographic lens according to claim 6,wherein at least said focus control means is supplied from said camerabody through one of said electrical contacts.
 16. A photographic lensaccording to claim 11, wherein at least said diaphragm control means issupplied from said camera body through one of said electrical contacts.17. A photographic lens according to claim 14, wherein at least saidpower zoom means is supplied from said camera body through one of saidelectrical contacts.
 18. A photographic lens according to claim 1,wherein said electrical contact group has a plurality of electricalcontacts which are electrically insulated from each other and which areprovided on the surface of a mount ring of a lens mount.
 19. Aphotographic lens according to claim 1, wherein said electrical contactgroup has at least one electrically insulated contact provided on thesurface of a mount ring of a lens mount, and at least one electronicallyinsulated contact provided inside a mount ring of a lens mount.
 20. Acamera body to which a photographic lens is detachably mounted,comprising:a group of electrical contacts provided on a camera bodymount to which said photographic lens is mounted; means for judging thetype of photographic lens based on the electrical contact connection ofsaid photographic lens; first means for controlling said photographiclens in response to a first set of information comprising a pair ofinformation of the electrical contacts as a whole and which represents afirst information type in which said photographic lens supplies onlysaid first information to the camera body; second means for controllingsaid photographic lens in response to a plurality of second informationwhich is peculiar to said photographic lens and which represent a secondinformation type in which said photographic lens supplies said secondinformation to said camera body through a memory means connect to saidelectrical contact group; and, third means for controlling saidphotographic lens in response to a third set of information whichrepresents a third information type in which said photographic lens hasan arithmetic/control means connected to said electrical contact groupin addition to said memory means, receiving and transmitting said thirdinformation from and to said camera body.
 21. A camera body according toclaim 20, further comprising an object distance measuring means fordetecting a defocus quantity in accordance with a luminous flux of lightthat is incident thereupon through said photographic lens;means fordriving a focus adjusting mechanism in accordance with said defocusquantity detected by said object distance measuring means; and means fortransmitting a driving power of said focus adjusting mechanism drivingmeans to a focus adjusting means of said photographic lens.
 22. A camerabody according to claim 21, wherein said second control means actuatessaid focus adjusting mechanism driving means in according with saiddefocus quantity of said object distance measuring means when a secondtype of photographic lens having a focus adjusting mechanism and anassociation mechanism which associates said focus adjusting mechanismand said focus adjusting mechanism driving means is mounted to saidcamera body.
 23. A camera body according to claim 22, wherein said thirdcontrol means sends said defocus quantity detected by said objectdistance measuring means to said arithmetic/control means through saidelectrical contact group, so that said arithmetic/control means detectsthe displacement of said focus adjusting mechanism in accordance withsaid defocus quantity to actuate a focus control means based on thedisplacement when a third type of photographic lens having a focusadjusting mechanism, focus control means for driving the focus adjustingmechanism and an arithmetic/control means is mounted to said camerabody.
 24. A camera body according to claim 23, wherein said thirdcontrol means sends said defocus quantity detected by said objectdistance measuring means to said arithmetic/control means through saidelectrical contact group, so that said arithmetic/control means detectsthe displacement of said focus adjusting mechanism driving means todetect said focus adjusting mechanism driving means based on thedisplacement when said third type of photographic lens having a focusadjusting mechanism which is driving by said association mechanism andsaid arithmetic/control means is mounted to said camera body.
 25. Acamera body according to claim 20, further comprising an exposurecontrol means for detecting a brightness of an object to be photographedso as to determine an F value and a shutter speed, and a diaphragmmechanism for driving a diaphragm driving means of said photographiclens in response to said exposure control means.
 26. A camera bodyaccording to claim 25, wherein said first control means actuates anexposure mechanism driving means in accordance with the F value detectedby said exposure control means when said first type of photographinglens is mounted to said camera body.
 27. A camera body according toclaim 25, wherein said second control means actuates said exposuremechanism driving means in accordance with the F value detected by saidexposure control means when said second type of photographing lens ismounted to said camera body.
 28. A camera body according to claim 25,wherein said third control means sends the F value detected by saidexposure means to said photographic lens through said electrical contactgroup to actuate said diaphragm control means in accordance with the Fvalue when said third type of photographic lens having a diaphragmmechanism and a diaphragm control means for driving the diaphragmmechanism is mounted to said camera body.
 29. A camera body according toclaim 21, wherein when said third type of photographic lens having apower zoom means, a focal length detecting means for detecting saidfocal length of said lens, a forward displacement detecting means fordetecting the forward displacement of a focus lens and anarithmetic/control means is mounted to said camera body, said thirdcontrol means sends data representing said defocus quantity detected bysaid object distance measuring means to said photographic lens throughsaid electrical contact group, so that said arithmetic/control meansdetects a magnification based on the information from a forwarddisplacement detecting means when said defocus quantity is zero and theinformation from said focal length detecting means, whereby the defocusdata is sent to said photographic lens to actuate a power zoom means sothat the magnification is made constant.
 30. A camera body according toclaim 21, wherein at least said focus control means is supplied fromsaid camera body through one of said electrical contacts.
 31. A camerabody according to claim 28, wherein at least said diaphragm controlmeans of said photographic lens is supplied through one of saidelectrical contacts.
 32. A camera body according to claim 29, wherein atleast said power zoom is supplied through one of said electricalcontacts.
 33. A camera body according to claim 20, wherein saidelectrical contact group has a plurality of electrical contacts whichare electrically insulated from each other and which are provided on asurface of a mount ring of a lens mount.
 34. A camera body according toclaim 20, wherein said electrical contact group has at least oneelectrically insulated contact provided on a surface of a mount ring ofa lens mount, and at least one electrically insulated contact providedinside a mount ring of a lens mount.
 35. A camera system, comprising:aphotographic lens, said photographic lens comprising:a group ofelectrical contacts which are selectively connected to a camera body;first information transfer means for transmitting a first set ofinformation peculiar to said lens through at least a part of saidelectrical contact group; second information transfer means fortransmitting a plurality of variable information peculiar to said lensthrough memory means connected to said electrical contact group to saidcamera body; third information transfer means for transmitting andreceiving information to and from said camera body through anarithmetic/control means connected said electrical contact group; andswitching means for selecting said first information transfer means,second information transfer means or third information transfer means,based on the electrical connection of said electrical contact group tosaid camera body; and means on said camera body for selectively couplingsaid photographic lens to said camera body, said camera bodycomprising:a group of electrical contacts provided on said couplingmeans to which said photographic lens is mounted; means for judging thetype of photographic lens based on the electrical contact connection ofsaid photographic lens; first means for controlling said photographiclens in response to a first set of information comprising a pair ofinformation of the electrical contacts as a whole and which represents afirst information type in which said photographic lens supplies onlysaid first information to the camera body; second means for controllingsaid photographic lens in response to a plurality of second informationwhich is peculiar to said photographic lens and which represent a secondinformation type in which said photographic lens supplies said secondinformation to said camera body through a memory means connect to saidelectrical contact group; and third means for controlling saidphotographic lens in response to a third set of information whichrepresents a third information type in which said photographic lens hasan arithmetic/control means connected to said electrical contact groupin addition to said memory means, receiving and transmitting said thirdinformation from and to said camera body.